The present invention relates to the art of controlling the actuation of a hydraulic output power unit. More specifically, the present invention relates to a valve assembly adapted for the actuation of a hydraulic motor.
The invention is particularly applicable to controlling the actuation of a hydraulic motor used for powering tractor mounted ditchers, mowers, sickle bars and other cutting apparatus utilized in the art of roadside maintenance and will be described with particular reference thereto. However, it will be appreciated by those skilled in the art that the invention has broader application and may also be adapted for use in many other environments.
Heretofore, various cutting tools have been mounted to tractors or other prime movers by assemblies which hold the cutting apparatus to the side of the tractor for cutting away vegetation or earth as may be required for road maintenance. Conventionally, a control valve utilized for controlling the operation of a hydraulic motor on such mobile cutting apparatus included a manual operating lever for controlling the flow rate of hydraulic fluid pumped therethrough. Each control valve also had a recirculating port for returning excess hydraulic fluid back to a reservoir via return lines. A pressure output line was connected with a hydraulic motor to power the motor. However, such conventional control valves have been prone to various problems.
Accordingly, it has been considered desirable to develop a new and improved valve assembly which would overcome the foregoing difficulties and others while providing better and more advantageous overall results.